Larval and early post-larval stages in the abbreviated development of <i>Heterosquilla tricarinata</i> (Claus, 1871) (Crustacea, Stomatopoda)

Abstract

Heterosquilla tricarinata was laboratory-cultured through its complete larval development and found to have one propelagic and two pelagic larval stages prior to metamorphosis to the juvenile. These larval stages, the first juvenile, and relevant portions of the second juvenile stage, are described and figured. Individual larvae do not change in size during intermoult periods. Larvae occurring in the plankton show a progressive decrease in mean size between early (September) and late (November) springtime. Reasons for this are suggested. The first pelagic stage of H. tricarinata is anatomically very advanced in development, and the number of pelagic stages very few, in comparison with other known stomatopod life-histories. Ecological implications of this are discussed in relation to the high-latitude distribution of the species. Comparison is made between the final pelagic stage of H. tricarinata and that of its congenor H. brazieri .